Various mechanical devices are designed to work under high pressure in a container. Normally, the safety requirements to reduce hazards are high, and consequently such containers have been made with thick walls. A reason for this may be the difficulty in estimating the load on such containers, with a combination of axial and tangential forces. Prior art containers which incorporate mechanical structures have therefore been heavy and expensive.
It is proposed to manufacture Stirling motors with a transmission housing incorporating one or more electrical generators which can also accommodate a gas volume and serve as a pressure accumulator for creating a counter pressure against the piston of the Stirling motor. Thus, the introduction of a shaft through the wall of the housing is not necessary.
U.S. Pat. No. 4,683,633 (Otters) discloses the use of a shell structure of metal sheets which are reinforced by windings of glass or carbon fibres. This structure is labour intensive at the manufacturing stage and does not remove the uncertainty of sizing, providing a container with a larger weight than acceptable, e.g. for use in a car. Stirling motors powering vehicles primarily are used in a hybrid connection with batteries and so heavy weight will be a particular disadvantage.
It has not been possible to replace steel with cast aluminium to reduce the weight, due to the unallowable concentration of stress at the transition between the cylinder of the Sterling motor and the transmission and generator casing.